I think the best setup would be 2 batteries and a car charger. Charge one while you use one.
Here's a note: Modern cars have two types of setups for the plugins. One turns off when the engine is turned off and the other stays on all the time. My Ram has both types. By the way you can't hurt the vehicle with a charger, it is fused. My gold wheel has a lead/acid gel cell. When it dies, I will replace it with a lithium battery They hold there charge for a year in storage. Hope this helps, Frank...-